Hub Maytech 90 mm 9055 issues when hot?


i have build a board with 2 FOC box , 1 custom 10S3P and a dual hub Maytech 9055

I use it in sensored / foc mode.

I works really well when the board is “cold” but after a few miles, I sometimes have less power or cogging at startup.

do you think it can be a problem with sensors ? or just with the motor ? i will try without sensors but if you have any similar experience …



do you monitor the vescs with a HM-Module (like the Metr Module)?

What type of cells are you using? It might just be voltage sag.

Yes I have a Hm10 with metr app

My battery is made of Sony VTC6 It works really good , even with full power, when the motors are cold

It it possible that I don’t have enough amp when my battery is around 35 V (after a ride - when motors are hot … ) Issues are just for start , when I ride it is ok

I dunno how to help you but I just thought you had a really nice looking board

What is max speed? Is this something new that developed or a problem you’ve had since you built it?

Thanks !

My top speed is between 35-40 km/h I think I had the problem since beginning

I will try without sensor and with battery discharged but motor colds to identify the problems

I don’t own a hub motor myself and have never have tried it but from my understanding they inherently get hot because the urethane covers up the motor instead of leaving it exposed for cooling like outrunners. The design of the Maytech hubs seem to confirm this in that the heat is being trapped and when there’s heat in your coils there’s more resistance, slowing you down. Other mainstream hubs like Meepo are integrated with the truck and have cone shape on the truck side for cooling as well as the truck helping dissipate the heat. Plus they’re limited to 35kph/22mph and tested at the factory to perform within these limits.

Also check the windings of the motor, a lot of times these motors rushed in mass production in China and the windings themselves are done poorly causing inefficiency. If you have enough money to spare I would recommend buying @Hummie hub motors. He hand winds them himself and checks that it is getting the right kv and is made of steel instead of aluminum. If you can wait there is also Carvon direct drives which you can choose your own wheel but that is pretty much unavailable because its only 1 guy producing it and he’s produced 25 in 8 months.

If I were you just go with belt driven or wait a couple more weeks for @Kug3lis to offer geared driven “direct” drives. Honestly this where the next level tech is.

If you do decide to remain in the hub motor game but just not Maytech hubs. Raptor 2 offers hub motors but that’ll cost you $800 per hub because they don’t sell standalone hubs. You’ll have to buy the complete then take apart the hub. You will have the best hub motors in the industry imo.

hi, thanks a lot for your reply. i was looking for carvon hub / direct drive. I think it is the best solution for eskate : no pulley, no belt, but you can choose your wheels , …

i will try to fix issues on my maytech but I know that it is cheap quality…

It may be a hub motor thing cause my Raptor 2 does the same thing, when it’s hot or the battery is low usually both things are happening at the same time I get cut outs or cogging from a stop. Also brakes suck at high speed and they kick in hard at a lower speed

Have you tired monitoring the Motor-Temp? What values do you get?

You have to take into consideration the higher Ohmic-Losses (High Amps->heat) and lack of cooling of those big Hubmotors…

So if the Motor-Temp limit is reached it can behave not normally.

Try limiting the Topspeed (via ERPM limit) and lower your Bat-Max, maybe that helps

I found this thread from 2016. The hub motor looks like your Maytech ones. He had overheating problem when running an RC esc but when he switched to Vesc BLDC mode the motors ran cooler. Try running it in BLDC and see what happens.

Thanks for your reply It seems to be a temperature issue. I will try to monitor motor temperature and I will check if I still have issue when I wait 20 min … I will keep you informed. Thanks

it sounds like classic voltage sag.